oj.uz

Submission #227165

# Submission time Handle Problem Language Result Execution time Memory
227165 2020-04-26T09:39:31 Z ho94949 Olympic Bus (JOI20_ho_t4) C++17
5 / 100
 1000 ms 1272 KB 
#include <bits/stdc++.h>
using namespace std;

const int MAXN = 200, MAXM = 50'000, INF = 0x3f3f3f3f;

int N, M;
int U[MAXM], V[MAXM], C[MAXM], D[MAXM];
bool issp[MAXM]; // is vertex contained in shortest path DAG? ((1, N) -> x, (1, N) <- x)

int adj[MAXN][MAXN]; int from[MAXN]; bool vis[MAXN];

int dis0[MAXN], dis0r[MAXN], disN[MAXN], disNr[MAXN], dis[MAXN];

int dijk(int s, int e)
{
    memset(dis, 0x3f, sizeof dis);
    memset(vis, 0, sizeof vis);
    dis[s] = 0;
    for(int iter = 0; iter<N; ++iter)
    {
        int minv = INF, mini = -1;
        for(int i=0; i<N; ++i) if(!vis[i])
            if(minv > dis[i])
            {
                minv = dis[i];
                mini = i;
            }
        if(mini == -1) break;
        if(mini == e) return minv;
        vis[mini] = true;
        for(int i=0; i<N; ++i) if(!vis[i])
            if(dis[i] > dis[mini] + adj[mini][i])
                dis[i] = dis[mini] + adj[mini][i];
    }
    return INF;
}

int exc(int e)
{
    memset(adj, 0x3f, sizeof adj);
    for(int i=0; i<M; ++i)
    {
        int u = U[i], v = V[i], c = C[i];
        if(i==e) swap(u, v);
        adj[u][v] = min(adj[u][v], c);
    }
    return dijk(0, N-1) + dijk(N-1, 0);
}

void SP(int s, int* S, int *E, int *dis)
{
    memset(adj, -1, sizeof adj);
    memset(dis, 0x3f, sizeof(int)*N);
    memset(vis, 0, sizeof vis);

    for(int i=0; i<M; ++i)
    {
        int u = S[i], v = E[i];
        if(adj[u][v] == -1 || C[adj[u][v]] > C[i])
            adj[u][v] = i;
    }
    dis[s] = 0;
    for(int iter=0; iter<N; ++iter)
    {
        int minv = INF, mini = -1;
        for(int i=0; i<N; ++i) if(!vis[i])
            if(dis[i] < minv)
                minv = dis[i], mini = i;
        if(mini == -1) break;


        vis[mini] = true;
        issp[from[mini]] = true;

        for(int i=0; i<N; ++i)
            if(!vis[i] && adj[mini][i]!=-1)
            {
                int e = adj[mini][i];
                if(dis[i] > dis[mini] + C[e])
                {
                    dis[i] = dis[mini] + C[e];
                    from[i] = e;
                }
            }
    }

}

int main()
{
    scanf("%d%d", &N, &M);
    for(int i=0; i<M; ++i)
    {
        scanf("%d%d%d%d", U+i, V+i, C+i, D+i);
        --U[i]; --V[i];
    }
    SP(0, U, V, dis0); SP(0, V, U, dis0r);
    SP(N-1, U, V, disN); SP(N-1, V, U, disNr);
    
    long long ans = dis0[N-1] + disN[0];
    for(int i=0; i<M; ++i)
    {
        long long ret = D[i];
        long long u = U[i], v = V[i], c = C[i];
        ret += exc(i);
        ans = min(ans, ret);
    }
    if(ans >= INF) ans = -1;
    printf("%lld\n", ans);
}

Compilation message

ho_t4.cpp: In function 'int main()':
ho_t4.cpp:104:19: warning: unused variable 'u' [-Wunused-variable]
         long long u = U[i], v = V[i], c = C[i];
                   ^
ho_t4.cpp:104:29: warning: unused variable 'v' [-Wunused-variable]
         long long u = U[i], v = V[i], c = C[i];
                             ^
ho_t4.cpp:104:39: warning: unused variable 'c' [-Wunused-variable]
         long long u = U[i], v = V[i], c = C[i];
                                       ^
ho_t4.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &N, &M);
     ~~~~~^~~~~~~~~~~~~~~~
ho_t4.cpp:94:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d%d", U+i, V+i, C+i, D+i);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 249 ms 512 KB Output is correct
2 Correct 7 ms 512 KB Output is correct
3 Correct 282 ms 556 KB Output is correct
4 Correct 374 ms 560 KB Output is correct
5 Correct 37 ms 512 KB Output is correct
6 Correct 9 ms 512 KB Output is correct
7 Correct 5 ms 512 KB Output is correct
8 Correct 5 ms 512 KB Output is correct
9 Correct 16 ms 512 KB Output is correct
10 Correct 501 ms 568 KB Output is correct
11 Correct 496 ms 632 KB Output is correct
12 Correct 504 ms 608 KB Output is correct
13 Correct 304 ms 564 KB Output is correct
14 Correct 306 ms 556 KB Output is correct
15 Correct 264 ms 608 KB Output is correct
16 Correct 365 ms 568 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1084 ms 1272 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 239 ms 512 KB Output is correct
2 Correct 15 ms 512 KB Output is correct
3 Execution timed out 1088 ms 1144 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #4
0 / 63.0

# Verdict Execution time Memory Grader output
1 Correct 249 ms 512 KB Output is correct
2 Correct 7 ms 512 KB Output is correct
3 Correct 282 ms 556 KB Output is correct
4 Correct 374 ms 560 KB Output is correct
5 Correct 37 ms 512 KB Output is correct
6 Correct 9 ms 512 KB Output is correct
7 Correct 5 ms 512 KB Output is correct
8 Correct 5 ms 512 KB Output is correct
9 Correct 16 ms 512 KB Output is correct
10 Correct 501 ms 568 KB Output is correct
11 Correct 496 ms 632 KB Output is correct
12 Correct 504 ms 608 KB Output is correct
13 Correct 304 ms 564 KB Output is correct
14 Correct 306 ms 556 KB Output is correct
15 Correct 264 ms 608 KB Output is correct
16 Correct 365 ms 568 KB Output is correct
17 Execution timed out 1084 ms 1272 KB Time limit exceeded
18 Halted 0 ms 0 KB -